5.2 KiB
Copyright
{ I feel this article needs to start by saying that copyright is shit. ~drummyfish }
Copyright (better called copyrestriction) is one of many types of so called intellectual property (IP), i.e. a legal concept that allows ownership of certain kind of information. Copyright specifically allows to own (i.e. restrict other people's rights to) artistic creations such as images, songs or texts, which include source code of computer programs. Copyright is not to be confused with trademark or patent. Copyright is symbolized by C in a circle or in brackets: (C).
When someone creates something that can even remotely be considered art, they automatically have copyright on it, without having to register it anywhere or let it be known anywhere. They then have practically full control over the work and can successfully sue anyone who basically just touches it in any way. Therefore any code without a license attached is implicitly fully owned by its creator (so called "all rights reserved") and can't be used by anyone without permission.
This current form of copyright (as well as other types of IP such as software patents) has been highly criticized by many people, even those who it's supposed to "protect" (e.g. small game creators). Strong copyright laws basically benefit corporations and "trolls" on the detriment of everyone else. It smothers creativity and efficiency by prohibiting people to use, remix and improve already existing works. Most people are probably for some form of copyright but still oppose the current extreme form which is pretty crazy: copyright applies to everything without any registration or notice and last usually 70 years (!!!) after the author has died (!!!). This is 100 years in some countries. In some countries it is not even possible to waive copyright to own creations. Some people are against the very idea of copyright (those may either use waivers such as CC0 or unlicense or protest by not using any licenses and simply ignoring copyright which however will actually discourage other people from reusing their works).
Prominent critics include Lawrence Lessig (who established free culture and Creative Commons) as a response), Nina Paley and Richard Stallman.
Copyright rules differ greatly by country, most notably the US measures copyright length from the publication of the work rather than from when the author died. It is possible for a work to be copyrighted in one country and not copyrighted in another. It is sometimes also very difficult to say whether a work is copyrighted because the rules have been greatly changing (e.g. a notice used to be required for some time), sometimes even retroactively copyrighting public domain works, and there also exists no official database of copyrighted works (you can't safely look up whether your creation is too similar to someone else's). All in all, copyright is a huge mess, which is why we choose free licenses and even public domain waivers.
Copyleft (also share-alike) is a concept standing against copyright, a kind of anti-copyright, invented by Richard Stallman in the context of free software. It's a license that grants people the rights to the author's work on the condition that they share its further modification under the same terms, which basically hacks copyright to effectively spread free works like a "virus".
Copyright does not apply to facts (including mathematical formulas) (even though the formulation of them may be copyrighted), ideas (though these may be covered by patents) and single words or short phrases (these may however still be trademarked). As such copyright can't e.g. be applied to game mechanics of a computer game (it's an idea). It is also basically proven that copyright doesn't cover computer languages (Oracle vs Google). Depending on time and location there also exist various peculiar exceptions such as the freedom of panorama for photographs or uncopyrightable utilitarian design. But it's never good to rely on these pecularities as they are specific to time/location and are often highly subjective, fuzzy and debatable. This constitutes a huge legal bloat and many time legal unsafety.
A work which is not covered by copyright (and any other IP) -- which is nowadays pretty rare due to the extent and duration of copyright -- is in the public domain.
Free software (and free art etc.) is not automatically public domain, it is mostly still copyrighted, i.e. "owned" by someone, but the owner has given some key rights to everyone with a free software license and by doing so minimized or even eliminated the negative effects of full copyright. The owner may still keep the rights e.g. to being properly credited in all copies of the software, which he may enforce in court. Similarly software that is in public domain is not automatically free software -- this holds only if source code for this software is available (so that the rights to studying and modifying can be executed).